rs1555016650

Positions:

• chr11-66347373-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_006876.3(B4GAT1):​c.173A>G​(p.Gln58Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000974 in 1,437,534 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000097 (0 hom.)
• Consequence: B4GAT1 NM_006876.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.74

Genes affected

B4GAT1 (HGNC:15685): (beta-1,4-glucuronyltransferase 1) This gene encodes a member of the beta-1,3-N-acetylglucosaminyltransferase family. This enzyme is a type II transmembrane protein. It is essential for the synthesis of poly-N-acetyllactosamine, a determinant for the blood group i antigen. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.1258704).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
B4GAT1	NM_006876.3	c.173A>G	p.Gln58Arg	missense_variant	1/2	ENST00000311181.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
B4GAT1	ENST00000311181.5	c.173A>G	p.Gln58Arg	missense_variant	1/2	1	NM_006876.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000974 AC: 14 AN: 1437534 Hom.: 0 Cov.: 31 AF XY: 0.0000112 AC XY: 8 AN XY: 713192

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000127

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A13 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 01, 2021

This sequence change replaces glutamine with arginine at codon 58 of the B4GAT1 protein (p.Gln58Arg). The glutamine residue is moderately conserved and there is a small physicochemical difference between glutamine and arginine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with B4GAT1-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.079
BayesDel_addAF	Benign	-0.13	T
BayesDel_noAF	Benign	-0.42
CADD	Benign	21
DANN	Uncertain	0.98
DEOGEN2	Benign	0.12	T
Eigen	Benign	-0.21
Eigen_PC	Benign	-0.0055
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Benign	0.70	T
M_CAP	Benign	0.024	T
MetaRNN	Benign	0.13	T
MetaSVM	Benign	-1.1	T
MutationTaster	Benign	0.97	D
PrimateAI	Uncertain	0.64	T
PROVEAN	Benign	-0.65	N
REVEL	Benign	0.10
Sift	Benign	0.084	T
Sift4G	Benign	0.42	T
Polyphen		0.16	B
Vest4		0.19
MutPred		0.21		Gain of MoRF binding (P = 0.0258);
MVP		0.076
MPC		0.90
ClinPred		0.45	T
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.31
gMVP		0.48

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1555016650; hg19: chr11-66114844;